Yes, thus any information or depth given on their characters should be valid, like how the Demon King/Meliodas viewed the knights as a nuisance and selfish brigade.
Information on this + MoC are pretty much the only valuable details which are canon in the movie, others are just bullshit.
Of course, Diane (without power-up) & King were apparently able to resist against Indura (whom I'm assuming is 200,000 +) which is beyond stupid in reality, but this is a movie, so meh.
The only feats in the movie worth considering is Meliodas VS Bellion considering how both of them are roughly commandment level, but even then, it's a stretch.
Obviously, for the most part the plot & feats of the characters inside movies of manga/anime are not actually canon, they're heavily stretched for entertainment value, otherwise Indura would've slaughtered everyone in a matter of seconds, which doesn't make for a good movie, does it?